The use of antioxidants has been proposed for therapeutic treatment and for other uses such as protecting polymers such as natural rubber and synthetic rubber from oxidation. Hindered phenols occur naturally, for example tocopherols (vitamin E), and have found use as antioxidants previously. Recently, free radicals have been postulated to have significant impact in tissue injury. Evidence suggests that the free radical mechanism has a significant impact on vascular injury and damage affecting nerve cells.
The use of phenylbutyl nitrone compositions for the treatment of oxidative tissue damage and gastric ulceration has been disclosed in U.S. Pat. Nos. 5,025,032 and 5,036,097 entitled "Phenylbutyl Nitrone Compositions and Methods For Treatment of Oxidative Tissue Damage" and "Phenylbutyl Nitrone Compositions and Methods for Prevention of Gastric Ulceration", respectively.
Research has demonstrated that nitrones select a location in membrane models and microsomes which is as polar and/or as protic as pure methanol as discussed in E. G. Janzen et al., "Locating spin traps in heterogeneous media by .sup.13 C NMR spectroscopy. Investigations in SDS micelles, DMPC vesicles and rat liver microsomes", J. Org. Chem. 54:2915- 2920 (1989). Thus, it is suggested that antioxidant molecules must be precisely located in the same volume compartment as where the free radical event occurs, or else the free radicals will not be quenched. Heretofore, such molecules have not been available. Therefore, development of new families of antioxidant molecules is necessary in order to provide molecules which will be effective against free radical damage at different biological sites. There has also been a need to provide antioxidant compositions which have no known toxic effect while providing a more effective free radical spin trap.
The present invention offers the advantages of a spin trap agent with no known toxic effects. Further, the invention offers the advantage of providing compounds highly efficient in the quenching of free radicals.